(1) If there is a vacancy on the ballot for a nonpartisan office after the time for filing and before the primary election, the vacancy may only be filled by a petition candidate after the primary election pursuant to sections 32-617 and 32-618.
(2) A vacancy shall exist on the ballot for the general election when (a) any person ceases to be a candidate for the office for which he or she filed a candidate filing form in the primary election and the number of candidates for office is less than twice the number of positions to be filled or (b) no person was nominated for the office in the primary election. If such a vacancy exists for a nonpartisan office, such vacancy may be filled by filing petitions for nomination pursuant to such sections no later than September 1 prior to the general election.